Trimming mechanism



Feb. 21, 1939. J. P was 2,147,725

TRIMMING MECHANISM Filed Sept. 1, 1936 z/ 2 Illl' 25 7 A .i'. 24

4, M j 4: I 53 fia 6 I'ZZ\ INVENTOR oh I? Was ATTORNE Patented Feb. 21, 1939 PATENT OFFICE 2,141,725. TRIMMING rmcnnmsm John P. Weis, Nyack, N. Y., assignor to Willcox' A; Gibbs Sewing Machine Company, New York, N. Y., a corporation of New York Application September 1, 1936, Serial No. 98,856

22 Claims. (01. 112-124) The present invention relates to trimming mechanisms for use on sewing machines. More particularly it relates to pinking mechanism for use on sewing machines, adapted to pink or zigzag cut one or more plies of material in predetermined marginal relation to a line of stitching, to prevent raveling and other adverse effects.

In recent years there have been a'number of efforts to provide pinking mechanisms adapted to operate coordinately with the regular seam forming instrumentalities of a sewing machine. Some of these have been very practical arrange- .ments and have met with considerable favor in the trade. However, most of these practical proposals have resulted in rather large, cumbersome and costly mechanisms.

Particularly, in most of these previous proposals complicated special driving connections were developed, to operate the rotatable or chopknife type cutter, such as a worm and worm gear mechanism associated with the top shaft of the sewing machine or an eccentric and pitman connection in the top or the bottom arm of the sewing machine.

Although it has long been a desideratum to provide a trimming mechanism of small compact, easily assembled, and interchangeable form and capable of economical production there have been practically no proposals, and none so far as applicant is aware, which have met with commercial success.

It is an important object of the present invention to provide a trimming mechanism for sewing machines which will be extremely simple,

" small and economical to manufacture and sell,

but which will nevertheless be capable of operating satisfactorily for a long period of time.

To this end the present invention provides a compact trimming mechanism which weighs but a few ounces, and which may be either built onto the sewing machine during its original manufacture or which may be in the form of an attachment readily securable to existing sewing machines.

A feature flowing from the attainment of this object is the provision of a complete trimming mechanism consisting of a very small quantity of parts all of which may be manufactured very economically and assembled very easily.

It is another important object of the present invention to provide a trimming mechanism which may be quickly placed in operation on sewing machines which have long been in the field, without the necessity of cutting out parts thereof in some special manner.

To this end the present invention has provided a trimming mechanism, in the form of an attachment which may be simply placed upon the regular work or cloth plate of the sewing machine and secured thereto by merely utilizing 5 existing throat plate or original attachment holding screw holes. A complemental feature is the provision of a trimming mechanism with an integral throat plate which may be fully located and secured on the sewing machine by placing andsecuring the throat plate thereof in the usual throat plate nest of the cloth plate.

It' is an important object of the present invention to provide a very small trimming mechanism and driving means therefor which may be placed centrally adjacent at the side of the needle to prevent puckering of the materials during pinking thereof.

One of the most important objects of the present invention is to provide a feeding mechanism which will be smooth and positive in its action and which will operate the cutter only upon each working or material advancing movement of the material feeding mechanism.

To accomplish this object the present inven- 25 tion contemplates the provision of a novel driving mechanism including a clutch associated with the rotatable cutter and with the feeding mechanism whereby positive operation of the clutch is accomplished upon each reciprocation of the feeding mechanism.

If the rotatable cutter does not travel coordinately with the travel of the feeding mechanism there is a danger of puckered material and spoiled work. In some of the pinking mechanisms heretofore proposed driving of the rotatable cutter was accomplished with pawl and ratchet mechanisms or with cooperating ratchets. However, mechanisms of the former type had the disadvantage of failure of the pawl to en- 40 gage with the teeth of the ratchet or the pawl driving more than the predetermined number of teeth because of an overthrow due to the momentum of the cooperating parts. Also, the latter proposal in which cooperating rigid or semi-rigid ratchet members were employed re- ;sulted in occasional topping or overriding-action which is a real disadvantage.

Another disadvantage with many of the proposals of the past was that no provision was made whereby the peripheral travel of the cutter could be equalized and coordinated with the travel of the feed dog, as when the machine is changed from 8 to 15 stitchesper inch or vice versa.

Some of the proposals of the past which inl cluded mechanism intended to insure absolute or an equal extent of travel to both the cutter and the feed dog did not include mechanism whereby travel of the cutter could be made greater or less than travel of the feed dog for the production of convex and concave edge effects for arm pads and other parts of wearing apparel, for example.

cognizance of these shortcomings prompted the objective of providing driving means for a trimming mechanism of extremely simple form adapted to effect travel of the cutter only when the feeding mechanism is actually advancing the material; mechanism wherein there will be no danger of teeth skipping or overriding to cause respectively no and excessive travel of the cutter; mechanism for insuring a coordinate travel of the rotatable cutter with the feeding mechanism whether the latter be set for 8, 10, or even 20 stitches per inch; and, mechanism for imparting greater or less travel to the rotatable cutter relative to the feeding mechanism whereby concave and convex pinked seams may be made.

Since greater pressure is required in order to cut certain materials and/or because a certain amount of wear occurs on the teeth of a cutter or on the cooperating surface it is desirable to make I certain adjustments, whereby it is possible to regulate the position of the cutter relative to the cooperating surfaces.

The present invention provides a very novel and extremely simple mechanism for this purpose constituting one of the important features of the invention. This feature includes the provision of a split section on the base and means such as a simple screw adapted to regulate the position of the cutter relative to the work support.

In some forms of work it is desirable to have the trimming cutter shiftable laterally relative to the needle bar and to the line of stitching whereby margins may be provided on the material extending varying extents from the line 0 stitching.

A feature of the invention, therefore, is the provision of a trimming mechanism with a means for shifting the cutter to positions at various distances relative to the needle bar and line of stitching. In its preferred form this means now includes a simple eccentric so associated with a member carrying the cutter, that the member and cutter may be moved positively relative to the needle bar.

A further feature is the provision of a bore in the base for holding a cutter supporting member and in the provision of a coextensive bore or housing in the base enveloping and protecting the cutter and/or the clutch.

Other objects, features and advantages will appear hereinafter.

In the drawing which illustrates the present preferred embodiments of the invention:

Figure l is a fragmentary showing of a conventional sewing machine with the trimming mechanism of the present invention attached thereto, as viewed from the end of the sewing machine and trimming mechanism.

Fig. 2 is a sectional view taken through the center of the trimming mechanism, on line 22 of Figs. 1 and 3.

Fig. 3 is an end view of the trimming mechanism looking toward the left as it is shown in Fig. 2.

Fig. 4 is a view very similar to Fig. 2 illustrating a modified form of the mechanism wherein mechanism for transverse shifting of the trimming mechanism is provided.

Fig. 51s a fragmentary view of a modified form of driving connection.

Fig. 6 is a cross-sectional view taken on line 6-6 of Fig. 5.

Fig. '7 is an enlarged fragmentary disclosure of the feed dog part of the mechanism.

Referring now in detail to the drawing which illustrates the present preferred embodiments of the invention it may be noted that only a small portion of a sewing machine 20 is shown with the trimming mechanism 2| of the present invention applied thereto. A complete showing of a sewing machine of any particular form might unnecessarily limit the present invention since it is intended that the trimming mechanism be applicable for use in combination with divers types of sewing machines including many of the divers types of sewing machines already in the field.

In the drawings the portion of the sewing machine 26 shown corresponds with the well-known Metropolitan sewing machine, many of which are in the field, and includes a lo er arm 22 supporting a cloth plate 23 with a preferably integral standard 24 rising therefrom to support, through an overhanging arm (not shown), a needle bar 25 and needle 26 for usual operation by conventional driving mechanism. Cooperating with the needle 26 is a looper 21 in a looper carrier 28 secured to a looper shaft 29, usually given both oscillatory and reciprocatory movement in timed relation with the needle 26 by the conventional driving mechanism, to impart needle loop taking and needle avoiding travel to the looper 21.

The trimming mechanism 2i of the present invention is adapted to be operated by feeding mechanism of the sewing machine in a particularly novel and advantageous manner. The feeding mechanism for operating the trimming mechanism may be of divers forms. Preferably it is of the conventional four motion type.

Illustrative of one form of feeding mechanism for operating the trimming mechanism 2| of the present invention, a conventional four motion feeding mechanism 36 is shown in the lower arm 22 in Fig. 1 of the drawing. This feeding mechanism comprises a feed lifter rod 3| and feed rocker rod 32 each given a predetermined extent of oscillatory movement by the conventional driving mechanism coordinately with the reciprocation of the needle 26 and movement of the looper 21.

The feed lifter rod is provided with a finger 33 preferably supporting a plurality of leaf springs 34 in a notch 35, the latter being connected through a notch 36 to a feed bar 31, as is clearly apparent in Fig. 1. A coil spring 36 connected to pins 39 and 46 further insures a close operating connection of the leaf springs 34 in the notches 35 and 36 and between the finger 33 and feed bar 31.

The feed rocker rod 32 is provided with a finger 4i secured to the rod by a yoke connection 42 and at its upper end is provided with a leaf spring connection 43 to the feed bar 31. The connection 43 includes a plurality of leaf springs 44 secured to the finger 4i with a screw 45 and to the feed bar 31 by a screw 46.

In its preferred form the feeding mechanism includes a separate feed dog 41 secured to the feed bar I! as by a screw 46, so that interchangeability and replacement may be easily and quickly effe'cted. However, if preferred, the feed dog 41 may be made integral with the feed bar 31. Or-

di'narily the cloth plate 23 is provided with a cutout or channel 49 to clear the feed dog 41 and looper 21 and, is provided with a nest 50 adapted to receive a throat plate 5| which is provided with cut-outs to clear the needle after it passes through the material and to clear the particular configuration of the feed dog, in the now well known manner.

The novel trimming. mechanism 2| provided by the present invention includes a base. 52 preferably having a subbase or work support 53 on the underside thereof and extending therefrom to form a throat plate 5! adapted to be inserted in the conventional throat plate nest 50 of existing machines, As shown, the work support 53 may, for economy, be made integral with the base 52. However,,if the base is made of cast iron and the work support is of considerable area so that steel or some stronger material is preferable for that section, the work support may be in the form of an initially separate plate of steel or like strong material secured to the underside of'the base. by suitable screws.

The trimming mechanism 2| in its present preferred form includes a rotatable cutter 54, prefj erably with zigzag cutting edges 55, positioned adjacent the needle and the line of stitching and having its axis of rotation extending transversely of and at a right angle to the line of stitching and the line of needle movement. A

non'rotatable and fixed member 58 in a suitable limit movement of the cutter longitudinally of the-member in one direction and to maintain the hub portion 8| of the. cutter against the shoulder 58 which limits movement of the cutter longitudinally of the member in the other direction.

. For imparting unidirectional movement to the cutter 54 any of the now well known and conven- Clutches of thisgeneral type are now well known and it will be readily appreciated upon viewing Fig. 6 that when the driver element or sleeve 68 is rotated in a clockwise direction it moves the rollers against the pressure of the springs to an ineffective position. When the driver sleeve is moved in a counterclockwise di- ,re'ction, however, the rollers through frictional engagement with the driver sleeve 68 and pressure from the springs 61 are caused to grip into view of the present invention to form it as a separate member and to secure the latter tothe cutter by means of pins, screws or any other suitable expedient, as shown in Figs. 4 and 5.

Preferably a removable anvil II is provided in the work support 53 underneath the cutter 84, which may be-of harder material than the work support to withstand wear for a greater period of time, and to make possible a replacement of Just this one small part rather than the complete work support 53 or base 52 after considerable wear occurs.

Complete driving of the cutter 54 coordinately with the material advancing movement of the feed dog 41 is effected by a novel driving connection II which in the present illustrated form includes an extension 12 at one side of; the feed dog 41 provided with a U-shaped aperture [3 adapted to receive an extension 14 on the clutch driving sleeve 88. Preferably this extension I4 at its lower end is in the form of a flat ball or flat circular disc 15.

Thus, as the feed dog 41 is given a four-way motion, in the usual manner by the feed lifter and rocker rods 3! and 32 hereinbefore described, the ball 15 rides in the aperture 13 to effect a back and forth oscillatory movement of the driver sleeve 58, through extension I4.

a raised operative work advancing position and is moving to the left as viewed in Fig. 1, the driver sleeve 88 through the rollers 55 eiiegts a rotation of the cutter. A .step-by-step unidirectional movement is seen, therefore, to be imparted to the cutter coordinately with the-movement of the regular feeding'mechanism.

By having the center of the ball 15 on the extension 14 one. line with the top of the feed dog 41 and with the periphery of the cutter 54 an extent of travel is imparted to the rotatable cutter absolutely equal to the work advancing travel of the feed dog '41. Such a fixed positioning of the centerof the ball 15 represents the simplest tom of the invention.

novel trimming mechanism. 2| may besecuredto the sewing machine 20 in any desired way. Because of ,the provision of the integral work-support 55 which extends from the base 52 to constitute a throat, plate ii, the trimming mechanism may be readily located in a proper position relative to the needle 26 by placing the throat plate iii in the conventional throat plate nest 50 in the cloth plate 25.

Preferably the base 52 of the trimming mechanism 2| isfllocated relative to the cloth plate 23, which togetherwith the throat plate 5| serves as a main work support 18, by providing a downwardly extending shoulder II on the basethat cooperates with an upwardly extending shoulder I8 formed on the cloth plate. .To hoidthe base 52 securely, in position a screw 19 is provided having an enlarged shank portion Ill terminating in a downwardly facing shoulder 8!. The screw, passing through the member 56,.the base "and into a. threaded hole 83 in, the cloth plate, draws the downwardly facing shoulder 5| into engagement with an upwardly iacing shoulder 82 in the base and thus effectively clamps the trimming mechanism 2! in place. A knurled head or knob means for tightening "and looseningthe' screw.

54" on the holding screw 18 serves as a convenient If desired, and as shown in Figs. 2 and 3, usual throat plate holding screws and 33 may be provided to pass through the throat plate BI and into the cloth plate 23.

.draw the shoulder 03 on the member I against the shoulder 01 formed in the bore 51 of the base As a particularly advantageous means for preventing engagement of an operator's fingers with the cutter 54 and for preventing working tools from dropping down onto the cutting edges II of the cutter 04 there is provided a housing 02 preferably formed integral with the base 32 and coextensive with the bore 51, to enclose both the clutch 04 and the cutter ll.

Of especial importance the present invention provides a novel regulating means 83 whereby the cutter may be properly located with respect to the work support 03, to impart different degrees oi pressure according to the material being cut, to compensate for slight irregularities in manuiacturing dimensions of the cutter or other parts, and to compensate for wear.

To this end a hole as is formed in the base, as by drilling, to extend transversely of and preferably below the bore 01, and a slot 95 is formed to extend from the hole to divide a portion 52a. of

,the base into an upper section 32b and a lower section 520. A regulating screw 38 in screw threaded relation with the section "b of the member and passing through enlarged and aligned holes 01 and 98 in the upper sectionllb to engage the lower section 520 completes the means making possible the proper positioning of the cutter relative to the work support 53.

As the regulating screw 96, which may for convenience be provided with a knurled head 00, is turned in one direction the section lib of member 30 is moved upwardly thereon relative to the lower section 520 of the base 52, which movement causes the reduced portion is carrying the cutter ll at the other end of the member to move downwardly toward the work support. when the screw 00 is turned in the other direction the upper section 02b of the portion 02a of the base carrying the section "b of the member II is permitted to return to its normal position relative to the lower section "c. A slight movement of the cutter 54 away from the work support is thereby permitted. Thus, a simple and positive means is provided for accomplishing absolute regulation of the cutter relative to the work support.

Fig. 4 discloses a modified form of the present invention diflering from thesimplest and main form disclosed in Figs. 1 through 3 and '1 hereinbei'ore described in detail in the provision of a means I" for shifting the cutter 04 and member 03 toward and away from the needle 20 and needle bar 2!. I

In achieving this end there is provided a modifled holding screw Ila for securing the base I to the cloth support 23, having a shank Ila, of less diameter than thesimplest form, which serves as a pivot for an eccentric sleeve member Ill in a transversely elongated hole I02 extending downwardly and transversely of the member I0 .111 'the'section "a. The width of the hole I02 longitudinally of the member 56 is equal to the outside diameter of the eccentric. Its width transversely of the member is approximately onehalf greater than the .outside diameter of the eccentric sleeve to permit a turning of the eccentric to efiect a longitudinal movement of the member 50 in the bore 51 of the base 52 without efiecting a transverse movement of the member.

To permit free longitudinal movement of the member 50 and associated clutch 64 and cutter 54, the base 52 is provided with a recess I03 adapted to clear the driver sleeve 68 of the clutch 04. Similarly, the work support 53 and the cloth plate 23 are provided with cut-outs I04 and I05 respectively to clear th eextension I4 and ball IS on the clutch driver sleeve.

A flanged knob I06, preferably knurled, at the top end of the eccentric sleeve I 0| is provided to turn the eccentric in the hole I 02 to effect the transverse shifting of the member 56 and cutter 54 toward and away from the needle 26. Thus, it is merely necessary to loosen the screw 19a slightly to disengage the head 84a thereof from frictinal engagement with the flanged knob I06 and to turn the eccentric IOI any desired extent, whereupon the eccentric moves the member 56 longitudinally in the bore 51 into divers positions relative to the needle.

Tightening of the screw 19a again locks the eccentric IOI in the adjusted position either by pressing the lower end I01 thereof against a shoulder 82a in the base 52 or by clamping the upper and lower faces I08 and I09 of the flanged knob I08 against the head 84a of the screw 19a and onto the top of the base 52 respectively. Concurrently, the screw 19a through its connection with the cloth plate 23 locks the base to the cloth plate. As with the first form of the invention, a regulating mechanism 93 including the regulating screw 86 is provided to variously locate the cutter 54 relative to the work support 53.

Fig. 5 discloses a further modified form of .the present invention diifering from the simplest form disclosed in Figs. 1 through 3 and '7 primarily in the provision of a means IIO for varying the movement of the cutter 5| with respect to that of the regular feeding mechanism. As shown, this means comprises an adjustable extension Ila on the driving sleeve 68 of the clutch 6| rather than the fixed extension H of the device of Figs. 1 through 3. It includes a screw III threaded into a finger III on the driver sleeve 60 of the clutch, and having an integral ball a at the lower end thereof adapted to fit in the U-shaped aperture I3 formed in the extension I2 at one side of the feed dog 41. The adjustable extension Ila of Fig. 5 cooperates with the feed dog 41 to rotate the cutter through the clutch 64 in the same manner as does the fixed extension of Fig. 1.

To accommodate the screw III, the member 56 is provided with an enlarged hole I I3 which permits the free movement of the upper part of the screw when it is oscillated with the driver sleeve ll of the clutch. Cut out portions i I4, 5 and iii in the member 56, the base 52 and cloth plate 23 are provided for the finger II2, the screw III and the ball 15a respectively.

By turning the screw III, which may have a tool receiving slot III in the upper end thereof, the center of the ball may be moved upwardly and downwardly relative to the working face of the feed dog and the periphery of the cutter 6|. When the center of the ball is on a line with the periphery of the cutter, a movement is imparted to the cutter equal to that of the feed dog. When, however, the center of the ball 15a, as viewed in Fig. 6, is moved to a position lower than the periphery of the cutter an arcuate movement is imparted to the cutter which is less than the movement of the feed dog. The reverse is true when the center of the ball is moved to a position within the periphery of the cutter. If desired this modified form of the invention may be incorporated in the form of the invention disclosed in Fig. 4 as well as in the form of the invention disclosed in Figs. 1 through 3.

Other variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

Having thus described the invention what is claimed as new is:

1. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of a. base; a work support; a rotatable cutter; a member in said base supporting the cutter relative to the work support; a friction clutch associated with said cutter; a feed bar in the feeding mechanism; and a single means on said clutch for directly connecting the latter to the feed bar continuously during a plurality of operations thereof.

2. In a trimming mechanism, for sewing machines having a needle bar and a feeding mechanism, the combination of a base; a work support; a rotatable cutter; a member movably mounted in said base adapted to support the cutter relative to the work support; means for longitudinally shifting said member in said base to variously locate the cutter relative to the needle bar; a clutch associated with said cutter;

, and means connecting said clutch to the feeding mechanism.

3. In a trimming mechanism, for sewing machines having a needle bar and a feeding mechanism, the combination of a base; a work support; a rotatable cutter; a member mounted for movement longitudinally in said base adapted to support the cutter relative tothe work support; means for shifting said member in said base relative to said needle bar; means for locking said member and cutter in various positions relative to the needle bar; a clutch associated with said cutter; and means connecting said clutch to the feeding mechanism.

4. In a trimming mechanism, for sewing ma- I chines having a feeding mechanism, the combination of a base; a work support; a rotatable cutter; a member in said base adapted to support the cutter relative to the work support; a clutch associated with said cutter; a feed bar in the feeding mechanism; means on said clutch for directly connecting the latter to the feed bar; and means associated with the last named means for varying the extent of movement imparted to ing said member and cutter in various positions laterally relative to the needle bar; a clutch associated with said cutter; a feed bar in said feeding mechanism; means for directly connecting said clutch to said feed bar; and means associated with the last named means forvarying the supporting said cutter; a clutch associated with the cutter; a feed dog in said feeding mechanism; and adjustable means directly connecting said clutch to the feed dog to vary and control movement of the cutter by the latter.

7.'In a trimming mechanism for sewing machines having a needle bar and a feeding mechanism, the combination of a base having a bore; a work support; a rotatable cutter; a member in said bore supporting said cutter; means for moving the member and cutter toward and away from the work support; a clutch associated with the cutter; a feed bar in said feeding mecha nism; and means on said clutch for directly connecting the latter to said feed bar.

8. In a trimming mechanism, for sewing machines having a needle bar and a feeding mechanism, the combination of a base having a bore extending toward said needle bar forming an integral coextensive bearing and housing; a work support; a cutter; a clutch; and a member in said bearing supporting said cutter and clutch relative to the work support, while the housing substantially encloses the clutch and cutter.

9. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of a base having a split section; a work support; a rotatable cutter supported by the base; and means associated with said split section for moving the latter to vary the pressure of the cutter on the work support.

10. In a trimming mechanism, for sewing machines having a needle bar and a feeding mechanism, the combination of a base having a split section; a work support; a rotatable cutter; a

member supporting said cutter; and a screw in said member cooperable with said split section for moving the latter to adjust said member and cutter relative to the work support.

11. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of a base; a work support; a rotatable cutter; a member in said base adapted to support the cutter relative to the work support; a clutch associated with said cutter; a feed bar in said feeding mechanism; and a ball and socket connection between said clutch and the feed bar.

12. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of abase; a work support; a rotatable cutter; a member in said base adapted to support the cutter relative to the work support; a clutch associated with said cutter; a feed bar in said feeding mechanism; and means including a shiftable ball connecting said clutch and feed bar.

13. In a trimming mechanism, for sewing machines having a needle bar and a feed mecha-' ter; a member in said base adapted to support the cutter relative to the work support; a clutch associated with said cutter; a feed dog in said feeding mechanism, having an aperture; and an extension on said clutch, associated with said aperture in the feed dog.

15. In a trimming mechanism, for sewing machines having a needle bar and a feed mechanism, the. combination of a base; a work support; a rotatable cutter; a member in said base adapted to support the cutter relative to the work support; means for regulating the position of the cutter relative to the needle bar and to the work support; a clutch associated with said cutter; a feed dog in said feeding mechanism, having an aperture; and an extension on said clutch, associated with said aperture in the feed dog.

16. In a trimming mechanism, for sewing machines having a needle bar, a cloth plate with throat plate cut out and a feeding mechanism including a feed dog, the combination of a base; a rotatable cutter supported by the base; a work support section connected to and extending from said base forming a throat plate adapted to be inserted in said cutout to. properly locate the base and cutter relative to the needle bar; a clutch associated with said cutter; and means connecting said clutch to the feeding-mechanism.

, 17. In a trimming mechanism for sewing machines having a needle bar and a feeding mechanism, the combination of a work support; a base; a rotatable cutter; a member movable longitudinally in said base and supporting the cutter relative to the needle bar and the work support; and an eccentric for moving said member in said base to locate said cutter in divers positions relative to said needle bar.

18. In a trimming mechanism for sewing machines having a needle bar and a feeding mechanism, the combination of a work support; a base; a rotatable cutter; a member movable longitudinally in said base and supporting the cutter relative to the needle bar and the work support; an eccentric movable to divers adjusted positions for shifting said member in said base to locate said cutter in divers positions relative to said needle bar; and screw means for locking said eccentric in said adjusted positions.

19. In a trimming mechanism for sewing ma chines having a feeding mechanism, the combination of a work support; a base; a rotatable cutter; a member in said base for supporting said cutter relative to the work support; a clutch associated with said cutter; a feed dog in said feeding mechanism, having an aperture; and an extension on said clutch, extending into. said aperture and adjustable therein to vary its operative length to thereby control the movement of said cutter by the feed dog.

20. In a trimming mechanism for sewing machines having a feeding mechanism, the combination of a work support; a base having a split therein dividing the same into an upper and a lower section; a rotary cutter; a member in said upper section for supporting said cutter relative to the work support; and' means for moving said upper section relative to the lower section to urge said cutter relative to the work support.

21. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of a base; a work support; a rotatable cutter; a member in said base supporting the cutter relative to the work support; a friction clutch associated with said cutter; a feed dog in said feeding mechanism; and an extension on said clutch extending to and operatively associated with said feed dog to continuously connect the latter to the clutch during a plurality of operations thereof.

22. In a trimming mechanism, for sewing machines having a feeding mechanism, the combination of a work support; a rotary cutter; means for supporting said cutter relative to the work support; a clutch associated with said cutter; a feed dog in said feeding mechanism, having an extension with a U-shaped aperture therein; and a screw on said clutch having a ball on the end thereof and extending into said aperture, said screw being adjustable to vary its operative length to thereby control movement of the cutter 

